Railway signaling



H. S. LOOMIS.

RAILWAY SIGNALING.

APPLICATION FILED AUG-1. 1'9.

1,33 1,5 1 4. Patented Feb. 24, 1920.

WITNESSES LVVE NTOR. I

HQ; ATTORNEY.

UNITED STATES PATENT OFFICE.

HAROLD S. LOOMIS, OF WILKINSBUBJG, PENNSYLVANIA, ASSIGNOR TO THE UNION SWITCH & SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION 01' PENNSYLVANIA;

RAILWAY SIGNALING.

Specification of Letters Patent.

Application filed August 1, 1917. Serial No. 188,835.

To all whom it may concern:

Be it known that I, HAROLD S. LOOMLS, a citizen of the United States, residing at Wilkinsbu-rg, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Railway Signaling, of which the following is a specification.

My invention relates to railway signaling.

One object of my invention is the provision, in combination with two signals operated by energy from a common source, of means for preventing simultaneous operation of the signals but for permitting the operation of either signal immediately upon completion of the'operation of the other. I thus avoid the necessity for two sources of energy, or for a common source of energy of sulficient capacity to operate the two signals at the same time.

I will describe one form of signaling system embodying my invention, and will then point out the novel features thereof in claims.

The accompanying drawing is a diagrammatic view showing one form of signaling system having a plied thereto one form of apparatus embo ying my invention.

Referring to the drawing, AB is a stretch of single track between two passing sidings E and F, over which stretch trafiic moves in both directions. Eastbound traffic through this stretch is governed by signals S, S and S located at intervals through the stretch, while westbound traffic through the stretch is governed by sig nals S S and S", also located atintervalsthrough the stretch.

The apparatus and circuits here shown.

for the control of the signals are similar to the apparatus and circuits shown in Letters Patent of the United States granted to Ronald A. McCann on July 17, 1917, No.

1,233,488. Briefly described, the system is as follows:

The stretch A-B is divided by insulated joints 3 into several successive sections, AC-, CD and DB, and, as here shown, a pair of opposing signals is located at each juncture of adjacent sections, although I do not'wish to be limited to this particular location of the signals. Each section is provided with one or more track circuits, ineluding track relays, for the control of the signals. As here shown, each section is divided by insulated joints 3 into two subsections, and each subsection is provided with a separate track circuit. For example, section AC is divided into two sub-sections AH and HC, the former sub-sec tion being provided with a track circuit comprisin a track battery I) and a track relay T. ach sub-section is similarly provided with a track circuit comprising the rails of the sub-section, a track battery I), and a track relay, the relay being designated by the reference character T with the same exponent-as that of the adjacent signal which governs trafiic through the sub-section.

Each signal is provided with a signal relay for the control thereof, each of which relays is designated by the reference character R with an exponent corresponding to the exponent of the-signal which the relay con- 1 trols. Each signal relay (except relays R 1 T, wire 10, contact 11 of relay T wire 12,

contact 7 of relay P, wire 44, relay R wires 13 and 14, and common wire 0 to battery G. The circuits for signal relays R, R and R are similar to those just traced for relay R The circuits for signal relays R and R are similar to that for relay R except that, as here shown, they are controlled only by the track relays for sections AC and D-B, respectively, and by certain contacts on relays P and P", respectively.

Each signal S is provided with control ling circuits governed by the corresponding relay R, whereby the signal indicates proceed or stop accordin as the relay is energized or deenergized. signals by their relays is as follows:

Each signal is of a usual type, comprising a semaphore biased by gravity to the stop position, an electric motor M for moving the signal to proceed position, and a 10 from the right-hand terminal of battery Gr 11' he control of these 100 circuit for holding device lays R and R through wires 31 and 32, contact 33 of relay R wire 34, motor M, wire 35, contact 36, wire 37, back contact 38 of a relay X", wire 39, relay X, wire 40, common wire 0 to the left-hand terminal of battery G Contact 36 is operated by signal S and is closed in all positions of the signal except the proceed position, in which position it is open. It will be seen, therefore, that when relay R is closed, motor M is operated to move signal S to the proceed position, provided that relay X is deenergized, and that the motor circuit becomes opened as soon as the signal reaches the 'proceed position.

The circuit for the holding device Q is the same as that for the motor up to and including wire 34, then it passes through wire 41, the holding device, wire 42, contact 43 of relay R and wire 14 to battery G It will be seen, therefore, that after the signal has been moved to its proceed position it will be held there as long as relay R remains energized.

The motor M and holding device Q for signal S are also supplied with energy from battery G and the circuits for these instrumentalit-ies are similar to those for the corresponding parts of signal 8. That is, the circuit for motor M of signal S is controlled byrelay R, contact 36 operated by the signal, and back contact 38 of relay X and this circuit includes relay X The Q of signal S is controlled by relay R:

Each relay X and X open its back contact when the motor circuit in which it is included is closed, and such relay then, of course, opens the motor circuit for the other signal. will be seen that the motors for signals S and S cannot be operated simultaneously.

Assume now that for any reason both reare deenergized, so that both signals S and S are at stop. and that relay R then becomes energized. The circuits for the motor and holding device of signal S are then closed, so that the motor starts to move the signal toward its proceed position. Relay X thus becomes energized. If, during this movement of signal S relay R becomes energized, the cir- M of signal S will not be is energized to cuit for motor closed because this circuit is open at contact 38 of relay X. As soon. however. as signal S" reaches its proceed position, contact 36 on this signal opens the circuit for the motor of the same signal. whereupon relay X becomes deenergized and so permits the circuit for the motor of signal S to be closed. Signal S is then moved to the proceed position.

The motor circuits for signals S and S? are similarly controlled by relays X and X".

It will be seen that, as thus far described,

ized relay P is provided From this it' as a train enteis the stretch AB from either end, all the signals governing traflic through the stretch in the direction opposite to that in which the train is moving will change to stop indication, and that as the train proceeds through the stretch the signals in its rear governing traflic in the direction in which the train is moving will change to stop passed by the train and will remain at stop until the train leaves the stretch. Means are provided, however, for at times rendering each of the signal relays ineffective to control the signal relay for the signal next in the rear, so that as a train proceeds through the stretch the signals in the rear of the train may change to proceed indication when the train has left the portions of the stretch through which they immediately govern traflic, thereby permitting a following train to pass through the stretch at a safe distance from the first train. This means, as here shown, is a branch around the signal relay contact which controls the signal relay neXt in the rear, and this branch is controlled by a polarized relay located adjacent the signal relay. Each of these polarized relays is designated by the reference character P, with the same exponent as that of the signal relay around whose contact it forms a branch. Each relay P is responsive only to reversals of current. and having once responded to current of one direction its contacts remain in the position to which they have been moved even after the relay is deenergized and until it is energized by current in the opposite direction. Each polarwith a normal and a"reverse energization circuit. which circuits are controlled by the adjacent track relay T, and also by a circuit controller K operated by the adjacent signal. For ex ample, the normal energization circuit for relay P is from the middle point of battery G through wires 17 and 18, relay P wire 19, upper point of contact 20 of relay R wire 21', contact a of circuit controller K (operated by signal S), wire 22, upper point of-contact 23 of relay T wire 24. and wire 4 to right hand terminal of battery G This normal circuit is provided with a branch which extends from wire 19, through back point of contact 20, wire 25. contact (Z of circuit controller K to wire The reverse energization circuit for relay P is from the middle point of battery G through wires 17 and 18, relay P wire19, lower point of contact 20, wire 25. contact (I, wire 22, lower point of contact 23 of relay T and wires 26 and 27 to the left hand terminal of battery G It is apparent that current flows through the winding of relay P in one direction or the other according as track relay T is energized or deenergized, provided that indication as they arev the circuit of re- 'proceed to sto or vice versa, but is opened when the signal is at either of these positions. Contact a. is closed only when the signal is in the stop position.

Each polarized relay P is provided with a normal and a reverse, energization circuit, which circuits are similar to those just described for relay P.

Current through relay P in the normal directio'ncauses contact fingers 7 v and 16 to swing to the right, while current in the reverse direction causes these fingers to swing to the left. The same is true of relay P To simplify the reading of the drawing, however, the connections to relays P and P are such that their contacts swing to the left when the current is normal, and to the right when the current is reverse.

The branch around contact 5 of relay R which is the contact which normally controls tact 29 the circuit for relay R,

relay R is from wire 4 through wire 15, contact 16 of relay 1?", wire 28-to wire 6. J

The operation of the apparatus during the passage of an eastbound car or train through the stretch AB, is as follows:

When a train enters sub-section A-H, it opens track relay T, thereby opening at conwhich in turn causes signal S to change to the stop indication. The opening of contact 11 of track relay T opens the circuit for signal relay B so that signal S chan es to the stop indication. The opening of re ay R opens at contact 30 the circuit for signal relay B so that signal S changes to stop,andthe opening of relay R opens at contact 30 the circuit for relay- R so that signal S likewise changes to the sto iiindication. As the train enters sub-section C, it opens track relay T but this has no effect on thesignals, because contacts .11 and 29 of this relay control the same circuits as do contacts 11 and .29 of relay T. As the train enters sub-' section C'L, it opens track relay T, thereby openin at contact 11 the circuit for relay R", where y signal S changes to stop. As circuit controller K, operated by signal S", sweeps over contact d the reverse energization circuit for relay i becomes closed,

so that the contacts of relay P are reversed,

thus bridging the contact of relay R in the circuit for relay B. When the entire train leaves sub-section H-C, the closing of track relay T closes the circuit for signal relay R, so that signal S then changes to proceed,

thereby permitting the following eastbound train to enter the stretch. The closing of track relay T also closes'at contact 11 thereof the circuit for relay R", but this circuit remains open at contact 7 of relay P hence signal S continues to indicate stop. When -S and relay P 4 signals from one the train passes signal S it places this nal at stop and reversc relay P, in the same way that it previously affected signal Relay It now'closes because its circuit is closed at contact 16 of relay P hencesignal S begins to clear. Immediately upon the closure of relay R},

the normal energization circuit for relay P "is closed so that the contacts of this relay swing back to the positions in which they are shown in the drawing. This reversal closes at contact 7 the circuit for relayR, thus. closing at the contacts of this relay "the cir This signal circuit, h'owcuit for signal S. ever, is open at contact 38 of relay X, which relay was picked up b the closure of the motor circuit for signa S hence signal S will not move until signal S has reached the proceed position.

The circuit for relay B being controlled by relay R signal S remains in the stop position while the train is in section D.B. As the 'train passes out of the stretch, relay R closes, thus causing signal S to move to the -proceed position, and also energizing relay P in the normal direction. 7 Relay R now closes, but the circuit for signal S remains open at contact 38 of relay X until signal S whereupon signal S changes -to proceed. Signal S of course, changes to the proceed position as soon as the train leaves the stretch. The parts of the apparatus are then again in the positions in which they are shown in the drawing.

The operation of the apparatus during the passage of an eastbound train through the stretch will be apparent from the operation just described during the passage of an eastbound train.

By providing the relays X and X to prevent simultaneous operation of signals S and S I am enabled to operate both of these battery G, which battery need be only of sufiicient capacity to operate but one of the signals at a time. This arrangement, therefore, reduces the initial cost of the battery, reduces the cost of renewals of the battery and reduces capacity of shelter which the additional relays X and X. The same is, of course, true as to battery G for signals S and S. a

It may be well to add, b way of explanation, that the resistance 0 each holding device Q is high, so. that the total current has reached the proceed position,

has to be provided for-bat-' tery. These reductions in costs more than offset the increased cost of the system due todrawn from battery G by these devices when both signals S and S are bein held in the proceed position is considerab y less than the current required for 'the operation of one signal motor. 7

Although I have shown and described only one form of apparatus embodymg my circuit also includin invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims Without departing from the spirit and scope of my invention.

Having thus described my invention, what lclaimisz W v .1. In combination, two signals, a source of current, an operating circuit for each signal' including said source, means'for opening each circuit upon completion of the operation of the corresponding signal, and

means included in said operating circuits for preventing simultaneous operation of the two signals.

2. In combination, two signals each biased to stop position, a motor'for each signal for moving the signal to a proceed position in opposition to its bias, a source of current, a circuit for each'motor including said source, two relays one included in each circuit, each a back contact of the relay in the other'circuit', and means operated by each signal for opening the circuit for the corresponding motor when the signal has reached its proceed position.

3. In combination, twosignals, a source of current, a circuit for each signal including said source, and two relays one included in each circuit, each circuit also including a back contact of the relay in the other circuit, whereby simultaneous operation of said signals by energy from said source is prevented.

4. In combination, two signals each biased to stop position, a motor for each signal for moving the signal to a proceed position in opposition to 1ts bias, a source of current, a circuit'fo'r'each motor including said source, means for opening each circuit upon completion of the movement of the corresponding signal to its proceed position, and means included in said circuits for preventing simultaneous operationof the two motors.

5'. In combination, two signals each biased to stop position, a motor for each signal for moving the signal to a proceed position in opposition to its bias, a source of current, a circuit'for each motor including said source, means for opening each circuit upon completion of the movement of the corresponding signal to its proceed position, means for each signal for holding the signal in said proceed position, and means included in said circuits for preventing simultaneous operation of the two motors.

6. In combination, a single source of current, two signals operated b current from said source, a circuit for eac signal, means for opening each circuit when the operation of the corresponding signal is completed, a contact in each circuit which contacts may be closed simultaneously, a second contact in each circuit, and means controlled by each circuit and operating when the circuit is closed for holding open the said second contact in the other circuit.

7. In combination, a single source of current, two signals operated by current from said source, a circuit for each signal, means for opening each circuit when the operation of the corresponding signal is completed,

means for closing said clrcuits simultaneously at one point in each circuit, and means controlled by each circuit and operating when the circuit is closed for holding the other circuit open at a second point.

In testimony whereof I aflix my signature in presence of two witnesses.

HAROLD S. LOOMIS. Witnesses: t

A. HERMAN WEGNER, FAY GLAscow. 

